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WDXS32 PGTW 161500 MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/PROGNOSTIC REASONING FOR TROPICAL CYCLONE 18S (EIGHTEEN) WARNING NR 022// RMKS/ 1. FOR METEOROLOGISTS. 2. 6 HOUR SUMMARY AND ANALYSIS. SUMMARY: INITIAL POSITION: 17.0S 113.9E INITIAL INTENSITY: 35 KTS GEOGRAPHIC REFERENCE: 318 NM NORTH OF LEARMONTH, AUSTRALIA MOVEMENT PAST 6 HOURS: NORTH-NORTHWESTWARD AT 03 KTS SIGNIFICANT WAVE HEIGHT: 15 FEET SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION: ANIMATED ENHANCED INFRARED SATELLITE IMAGERY DEPICTS TROPICAL CYCLONE (TC) 18S (EIGHTEEN) WITH IMPROVED DEEP CONVECTIVE BURSTS OVER A BROAD LOW-LEVEL CIRCULATION CENTER (LLCC). A 161038Z SSMIS 91 GHZ SATELLITE MICROWAVE IMAGE REVEALS THE DEEP CONVECTION STRADDLING EITHER SIDE OF THE LLCC IN THE WESTERN AND EASTERN QUADRANTS OF THE SYSTEM. ENVIRONMENTAL ANALYSIS INDICATES THAT TC 18S IS IN A MARGINAL ENVIRONMENT FOR INTENSIFICATION WITH MODERATE WESTWARD OUTFLOW ALOFT, LOW TO MODERATE (15-20 KTS) EASTERLY VERTICAL WIND SHEAR, AND WARM (29-30 C) SEA SURFACE TEMPERATURES. THE INITIAL POSITION IS PLACED WITH LOW CONFIDENCE BASED ON THE AFOREMENTIONED SSMIS SATELLITE MICROWAVE IMAGE DEPICTING A BROAD LLCC, AND DUE TO THE FACT THAT THE LLCC IS OBSCURED BY THE CONVECTIVE BURSTS. THE INITIAL INTENSITY OF 35 KTS IS ASSESSED WITH MEDIUM CONFIDENCE BASED ON THE OBJECTIVE AND SUBJECTIVE INTENSITY ESTIMATES LISTED BELOW. INITIAL WIND RADII BASIS: PERSISTENCE CURRENT STEERING MECHANISM: COMPETING STEERING ENVIRONMENT AGENCY DVORAK AND AUTOMATED FIXES: PGTW: T2.0 - 30 KTS KNES: T2.0 - 30 KTS DEMS: T2.0 - 30 KTS APRF: T2.0 - 30 KTS CIMSS AIDT: 39 KTS AT 161300Z CIMSS DPRINT: 32 KTS AT 161200Z FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: MARGINAL VWS: 15-20 KTS SST: 29-30 CELSIUS OUTFLOW: MODERATE WESTWARD ANALYSIS CONFIDENCE: INITIAL POSITION: LOW INITIAL INTENSITY: MEDIUM INITIAL WIND RADII: LOW 3. FORECAST REASONING. SIGNIFICANT FORECAST CHANGES: THERE ARE NO SIGNIFICANT CHANGES TO THE FORECAST FROM THE PREVIOUS WARNING. FORECAST DISCUSSION: TC 18S IS CURRENTLY SLOWLY TRACKING NORTH- NORTHWESTWARD WHILE LOCATED WITHIN A COMPETING STEERING ENVIRONMENT. A NEAR EQUATORIAL RIDGE TO THE NORTH AND A SUBTROPICAL RIDGE TO THE SOUTH ARE CAUSING THE SYSTEM TO DRIFT SLOWLY IN A QUASI-STATIONARY FASHION. TC 18S IS FORECAST TO MAINTAIN A WEAK STEERING MECHANISM OVER THE NEXT 48 HOURS. DURING THIS TIME THERE IS A VARIETY OF DIFFERENT TRACKS THE SYSTEM COULD TAKE, AND THE MODEL GUIDANCE SUGGESTS THAT. TC 18S IS FORECAST TO TRACK SLOWLY NORTHWESTWARD UNTIL TAU 12. AFTER TAU 12, TC 18S IS FORECAST TO START A SOUTHWESTWARD TURN AND MEANDER SOUTHWARD FROM TAU 24-48. AFTER TAU 48, THE STEERING MECHANISM WILL BE MORE DEFINED, AND THE SYSTEM IS EXPECTED TO TRACK WESTWARD ALONG THE NORTHERN PERIPHERY OF A SUBTROPICAL RIDGE (STR) FOR THE REMAINDER OF THE FORECAST PERIOD WITH TRACK SPEEDS INCREASING. REGARDING INTENSITY, THE JTWC INTENSITY FORECASTS HAS TC 18S SLOWLY INTENSIFYING TO 55 KTS BY TAU 120. TC 18S IS ANTICIPATED TO REMAIN IN A MARGINAL ENVIRONMENT, BUT AS THE STEERING PATTERN IMPROVES AND TRACK SPEEDS INCREASE, THE SYSTEM IS EXPECTED TO GRADUALLY INTENSIFY. MODEL DISCUSSION: NUMERICAL MODEL GUIDANCE REMAINS IN RELATIVELY POOR AGREEMENT, ESPECIALLY THROUGH TAU 72, AS IS SOMEWHAT EXPECTED DUE TO THE COMPETING STEERING MECHANISM. AS SUCH, THE TRACK FORECAST CONFIDENCE IS ASSESSED WITH OVERALL LOW CONFIDENCE. GFS HAS BACKED OFF ON TRACKING THE SYSTEM FAR SOUTH AND THEN NORTH, AND COINCIDES WITH THE REST OF THE GUIDANCE BETTER THIS CYCLE. NAVGEM REMAINS THE OUTLIER BY TRACKING THE SYSTEM STRAIGHT SOUTHWARD THROUGH TAU 48 BEFORE MAKING THE WESTWARD TURN. THE JTWC INTENSITY FORECAST CLOSELY ALIGNS TO THE JTWC INTENSITY CONSENSUS. A VERY LARGE INTENSITY SPREAD OF 80KTS IS PRESENT AMONG INTENSITY CONSENSUS MEMBERS BY TAU 120, LENDING LOW CONFIDENCE TO THE OVERALL INTENSITY FORECAST. FORECAST CONFIDENCE: TRACK 0 - 72 HR: LOW TRACK 72-120 HR: LOW INTENSITY 0 - 72 HR: LOW INTENSITY 72-120 HR: LOW// NNNN
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AXAU01 APRF 161857 IDW27600 TROPICAL CYCLONE TECHNICAL BULLETIN: AUSTRALIA - WESTERN REGION Issued by AUSTRALIAN BUREAU OF METEOROLOGY TROPICAL CYCLONE WARNING CENTRE at: 1857 UTC 16/03/2024 Name: Tropical Low Identifier: 08U Data At: 1800 UTC Latitude: 17.4S Longitude: 113.9E Location Accuracy: within 30nm (55 km) Movement Towards: west (270 deg) Speed of Movement: 1 knots (2 km/h) Maximum 10-Minute Wind: 25 knots (45 km/h) Maximum 3-Second Wind Gust: 45 knots (85 km/h) Central Pressure: 998 hPa Radius of 34-knot winds NE quadrant: Radius of 34-knot winds SE quadrant: Radius of 34-knot winds SW quadrant: Radius of 34-knot winds NW quadrant: Radius of 48-knot winds NE quadrant: Radius of 48-knot winds SE quadrant: Radius of 48-knot winds SW quadrant: Radius of 48-knot winds NW quadrant: Radius of 64-knot winds: nm ( km) Radius of Maximum Winds: nm ( km) Dvorak Intensity Code: T1.5/2.0/S0.0/24HRS STT:W0.5/06HRS Pressure of outermost isobar: 1002 hPa Radius of outermost closed isobar: 120 nm (220 km) FORECAST DATA Date/Time : Location : Loc. Accuracy: Max Wind : Central Pressure (UTC) : degrees : nm (km): knots(km/h): hPa +06: 17/0000: 17.4S 113.9E: 045 (085): 025 (045): 998 +12: 17/0600: 17.4S 113.8E: 060 (105): 030 (055): 995 +18: 17/1200: 17.4S 113.8E: 065 (120): 030 (055): 995 +24: 17/1800: 17.4S 113.7E: 070 (130): 030 (055): 995 +36: 18/0600: 17.5S 113.6E: 090 (165): 030 (055): 995 +48: 18/1800: 17.6S 113.4E: 100 (190): 030 (055): 995 +60: 19/0600: 17.6S 113.1E: 110 (200): 030 (055): 996 +72: 19/1800: 17.3S 112.1E: 120 (220): 030 (055): 997 +96: 20/1800: 16.7S 109.6E: 145 (265): 040 (075): 992 +120: 21/1800: 16.8S 106.1E: 185 (340): 045 (085): 989 REMARKS: Tropical Low 08U unlikely to develop significantly in the next few days. Intensity is 25 kn based on recent (1300 UTC) scatterometry and Dvorak. Dvorak analysis: DT is unclear. A D- trend gives MET 2.0, PAT 1.5, FT of 1.5 and CI or 2.0. Recent objective guidance: ADT 45kn, AiDT 37kn, DPRINT 30kn (all 1-min average) (SATCON N/A). ADT remains higher than what scatterometry indicated. Convection continues to fluctuate, and the recent isolated spots of deep convection north and south of centre, both with frequent lightning. However, significantly more deep convection is required to moisten the circulation to enable sustained deep convection about the centre and development. While it is possible the environment improves on Sunday and Monday with lower shear, the most recent NWP now indicates a general delay for development until Wednesday. Somewhat surprisingly NWP suggests further intensification despite what appears to be a somewhat dry environment and only upper level outflow to the south. The official intensity forecast remains below most model guidance as a result. 08U has been moving slowly to the west as the ridge to the south is dominating the steering influences of the monsoonal flow to the north. The ridge is weakening so slow and erratic motion will occur until during Tuesday. The ridge should build from Tuesday ensuring a westerly track is maintained in the following days. Copyright Commonwealth of Australia == The next bulletin for this system will be issued by: 17/0130 UTC.
Time (AWST) Intensity Category Latitude
(decimal deg.)Longitude
(decimal deg.)Estimated Position
Accuracy (km)0hr 2 am March 17 tropical low 17.4S 113.9E 55 +6hr 8 am March 17 tropical low 17.4S 113.9E 85 +12hr 2 pm March 17 tropical low 17.4S 113.8E 105 +18hr 8 pm March 17 tropical low 17.4S 113.8E 120 +24hr 2 am March 18 tropical low 17.4S 113.7E 130 +36hr 2 pm March 18 tropical low 17.5S 113.6E 165 +48hr 2 am March 19 tropical low 17.6S 113.4E 190 +60hr 2 pm March 19 tropical low 17.6S 113.1E 200 +72hr 2 am March 20 tropical low 17.3S 112.1E 220 -
WTXS32 PGTW 162100 MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/TROPICAL CYCLONE 18S (EIGHTEEN) WARNING NR 023// RMKS/ 1. TROPICAL CYCLONE 18S (EIGHTEEN) WARNING NR 023 01 ACTIVE TROPICAL CYCLONE IN SOUTHIO MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE WIND RADII VALID OVER OPEN WATER ONLY --- WARNING POSITION: 161800Z --- NEAR 16.7S 113.8E MOVEMENT PAST SIX HOURS - 340 DEGREES AT 03 KTS POSITION ACCURATE TO WITHIN 060 NM POSITION BASED ON CENTER LOCATED BY SATELLITE PRESENT WIND DISTRIBUTION: MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT WIND RADII VALID OVER OPEN WATER ONLY REPEAT POSIT: 16.7S 113.8E --- FORECASTS: 12 HRS, VALID AT: 170600Z --- 16.7S 113.5E MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 034 KT WINDS - 000 NM NORTHEAST QUADRANT 060 NM SOUTHEAST QUADRANT 060 NM SOUTHWEST QUADRANT 000 NM NORTHWEST QUADRANT VECTOR TO 24 HR POSIT: 240 DEG/ 01 KTS --- 24 HRS, VALID AT: 171800Z --- 16.8S 113.3E MAX SUSTAINED WINDS - 040 KT, GUSTS 050 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 034 KT WINDS - 060 NM NORTHEAST QUADRANT 070 NM SOUTHEAST QUADRANT 070 NM SOUTHWEST QUADRANT 050 NM NORTHWEST QUADRANT VECTOR TO 36 HR POSIT: 225 DEG/ 01 KTS --- 36 HRS, VALID AT: 180600Z --- 16.9S 113.2E MAX SUSTAINED WINDS - 040 KT, GUSTS 050 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 034 KT WINDS - 050 NM NORTHEAST QUADRANT 070 NM SOUTHEAST QUADRANT 070 NM SOUTHWEST QUADRANT 060 NM NORTHWEST QUADRANT VECTOR TO 48 HR POSIT: 285 DEG/ 02 KTS --- EXTENDED OUTLOOK: 48 HRS, VALID AT: 181800Z --- 16.8S 112.8E MAX SUSTAINED WINDS - 045 KT, GUSTS 055 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 034 KT WINDS - 060 NM NORTHEAST QUADRANT 080 NM SOUTHEAST QUADRANT 090 NM SOUTHWEST QUADRANT 070 NM NORTHWEST QUADRANT VECTOR TO 72 HR POSIT: 275 DEG/ 02 KTS --- 72 HRS, VALID AT: 191800Z --- 16.7S 111.9E MAX SUSTAINED WINDS - 045 KT, GUSTS 055 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 034 KT WINDS - 060 NM NORTHEAST QUADRANT 090 NM SOUTHEAST QUADRANT 090 NM SOUTHWEST QUADRANT 080 NM NORTHWEST QUADRANT VECTOR TO 96 HR POSIT: 285 DEG/ 05 KTS --- LONG RANGE OUTLOOK: --- 96 HRS, VALID AT: 201800Z --- 16.2S 109.8E MAX SUSTAINED WINDS - 050 KT, GUSTS 065 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 050 KT WINDS - 000 NM NORTHEAST QUADRANT 030 NM SOUTHEAST QUADRANT 030 NM SOUTHWEST QUADRANT 000 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 070 NM NORTHEAST QUADRANT 110 NM SOUTHEAST QUADRANT 110 NM SOUTHWEST QUADRANT 080 NM NORTHWEST QUADRANT VECTOR TO 120 HR POSIT: 270 DEG/ 08 KTS --- 120 HRS, VALID AT: 211800Z --- 16.3S 106.4E MAX SUSTAINED WINDS - 055 KT, GUSTS 070 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 050 KT WINDS - 040 NM NORTHEAST QUADRANT 050 NM SOUTHEAST QUADRANT 050 NM SOUTHWEST QUADRANT 040 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 080 NM NORTHEAST QUADRANT 120 NM SOUTHEAST QUADRANT 120 NM SOUTHWEST QUADRANT 090 NM NORTHWEST QUADRANT --- REMARKS: 162100Z POSITION NEAR 16.7S 113.7E. 16MAR24. TROPICAL CYCLONE 18S (EIGHTEEN), LOCATED APPROXIMATELY 336 NM NORTH OF LEARMONTH, AUSTRALIA, HAS TRACKED NORTH-NORTHWESTWARD AT 03 KNOTS OVER THE PAST SIX HOURS. MINIMUM CENTRAL PRESSURE AT 161800Z IS 999 MB. MAXIMUM SIGNIFICANT WAVE HEIGHT AT 161800Z IS 14 FEET. NEXT WARNINGS AT 170300Z, 170900Z, 171500Z AND 172100Z. // NNNN
WDXS32 PGTW 162100 MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/PROGNOSTIC REASONING FOR TROPICAL CYCLONE 18S (EIGHTEEN) WARNING NR 023// RMKS/ 1. FOR METEOROLOGISTS. 2. 6 HOUR SUMMARY AND ANALYSIS. SUMMARY: INITIAL POSITION: 16.7S 113.8E INITIAL INTENSITY: 35 KTS GEOGRAPHIC REFERENCE: 336 NM NORTH OF LEARMONTH, AUSTRALIA MOVEMENT PAST 6 HOURS: NORTH-NORTHWESTWARD AT 03 KTS SIGNIFICANT WAVE HEIGHT: 14 FEET SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION: ANIMATED ENHANCED INFRARED (EIR) SATELLITE IMAGERY DEPICTS TROPICAL CYCLONE (TC) 18S WITH A SUBSTANTIALLY OBSCURED LOW LEVEL CIRCULATION CENTER (LLCC) UNDER FLARING CONVECTION. LOW-LEVEL CLOUDS BAND INTO THE MOIST CENTER FROM THE WEST AND EAST AS DRY AIR ENTRAINS FROM THE NORTHWEST. THE ANIMATED EIR SUGGESTS THAT SYSTEM HAS BECOME MORE VERTICALLY ALIGNED OVER THE LAST SIX HOURS AS THE LLCC HAS TUCKED UNDER THE EASTERN EDGE OF THE CONVECTION. ON THE UPPER-LEVELS, WEAK OUTFLOW DRIFTS WESTWARD AND POLEWARD. AS THE SYSTEM HAS REMAINED QUASI-STATIONARY (QS) WHILE IN A COMPETING STEERING ENVIRONMENT OVER THE LAST COUPLE OF DAYS, WEAK OCEANIC UPWELLING HAS COOLED THE SEA SURFACE TEMPERATURES (SST) THOUGH SSTS REMAIN FAVORABLE BETWEEN 28-29C. A TIGHT GRADIENT OF MODERATE EASTERLY VERTICAL WIND SHEAR (VWS) REMAINS OVER THE SYSTEM. THE INITIAL POSITION WAS DETERMINED WITH MEDIUM CONFIDENCE USING ANIMATED EIR DEPICTING LOW-LEVEL TURNING, HOWEVER THE UPPER-LEVELS OBSCURE THE MAJORITY OF THE LLCC. THE POSITION WAS FURTHER SUPPORTED USING A 161745Z 91GHZ AMSR-2 MICROWAVE IMAGE SHOWING A BROAD REGION OF LOW-LEVEL TURNING. THE INTENSITY WAS ASSESSED WITH LOW CONFIDENCE BASED ON THE AGENCY AND OBJECTIVE FIXES LISTED BELOW. INITIAL WIND RADII BASIS: PERSISTENCE CURRENT STEERING MECHANISM: A COMPETING STEERING ENVIRONMENT ON THE LOW TO MID LEVELS BETWEEN A NEAR EQUATORIAL RIDGE (NER) TO THE NORTH AND A WEAKENING SUBTROPICAL RIDGE (STR) TO THE SOUTHEAST. AGENCY DVORAK AND AUTOMATED FIXES: PGTW: T2.0 - 30 KTS KNES: T1.5 - 25 KTS DEMS: T1.5 - 25 KTS APRF: T1.5 - 25 KTS CIMSS ADT: 45 KTS AT 161740Z FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: MARGINAL VWS: 20-25 KTS SST: 29-30 CELSIUS OUTFLOW: WEAK RADIAL ANALYSIS CONFIDENCE: INITIAL POSITION: MEDIUM INITIAL INTENSITY: LOW INITIAL WIND RADII: LOW 3. FORECAST REASONING. SIGNIFICANT FORECAST CHANGES: THERE ARE NO SIGNIFICANT CHANGES TO THE FORECAST FROM THE PREVIOUS WARNING. FORECAST DISCUSSION: TC 18S IS FORECAST TO REMAIN IN A QS STATE OVER THE NEXT 36 HOURS, MEANDERING TO THE WEST INITIALLY THROUGH THE FIRST TWELVE HOURS BEFORE TRACKING SOUTHWEST AS THE STR TO THE SOUTHEAST WEAKENS. WHILE IN THE REGION OF WEAKNESS, IT IS POSSIBLE THAT THERE MAY BE UNANTICIPATED DIRECTIONAL DRIFTING, EVEN LOOPING OF THE TRACK. BETWEEN TAU 48 AND 72, ANOTHER STR TO THE SOUTHEAST EXTENDING OVER WESTERN AUSTRALIA IS EXPECTED TO BUILD AND DRIVE TC 18S TO THE WEST, PICKING UP TO A TRACK SPEED OF 8KTS BY THE END OF THE FORECAST PERIOD. THE SYSTEM IS FORECAST TO MEAGERLY INTENSIFY TO 40KTS BY TAU 36 AND TO 45KTS BY TAU 72 DESPITE A DECREASE IN VWS AND IMPROVING CONDITIONS FOR OUTFLOW PRIMARILY DUE TO A RELATIVE DECREASE IN SST AND OCEAN HEAT CONTENT (OHC) AS THE SYSTEM REMAINS IN THE AREA FOR THE FIRST 48 HOURS. ONCE TC 18S MOVES OUT OF THE REGION, IT IS FORECAST TO INTENSIFY STEADILY TO 55KTS BY THE END OF THE FORECAST PERIOD AS THE SYSTEM MOVES INTO AN ENVIRONMENT LOWER VWS, MODERATELY IMPROVED OUTFLOW, BUT ALSO RELATIVELY LOW SSTS AND OHC. MODEL DISCUSSION: DETERMINISTIC MODEL GUIDANCE IS IN BETTER AGREEMENT THAT TC 18S WILL REMAIN QS OVER THE NEXT 48 HOURS BEFORE TRANSITIONING WEST AS A STR OVER THE AUSTRALIAN CONTINENT BUILDS. BOTH ECMWF AND THE ECMWF ENSEMBLE DRIFT THE SYSTEM TO THE NORTHWEST AND TAKE AN EASTWARD LOOP BEFORE DIPPING SOUTHWEST CONTINUING ON ITS WESTWARD TRACK BY TAU 72. EXCLUDING THE OUTLIER OF NAVGEM, THE CROSS-TRACK ERROR IS 250NM BY TAU 120. THE JTWC INTENSIFY GUIDANCE REMAINS SIGNIFICANTLY INCONGRUENT AS THE INTENSITY GUIDANCE HAS A 125KT SPREAD BY THE END OF THE FORECAST PERIOD. THE HWRF INTERPOLATION FORECASTS A PEAK OF 150KTS, HWRF TRAILING BEHIND AT 110KTS BY TAU 120 WHILE COAMPS-TC FORECASTS THAT THE SYSTEM WILL REMAIN STAGNANT AT 35KTS BY TAU 84. THE JTWC FORECAST WAS ASSESSED WITH LOW CONFIDENCE, BALANCING THE IMPROVEMENT IN VORTEX STRUCTURE AS VWS INCREASES BUT ALSO ACKNOWLEDGING THE LOW OHC SUPPORTING THE CYCLONE. FORECAST CONFIDENCE: TRACK 0 - 72 HR: LOW TRACK 72-120 HR: LOW INTENSITY 0 - 72 HR: LOW INTENSITY 72-120 HR: LOW// NNNN
最后于 2024-03-17 12:00:00 被ygsj24编辑 ，原因： -
AXAU01 APRF 170043 IDW27600 TROPICAL CYCLONE TECHNICAL BULLETIN: AUSTRALIA - WESTERN REGION Issued by AUSTRALIAN BUREAU OF METEOROLOGY TROPICAL CYCLONE WARNING CENTRE at: 0043 UTC 17/03/2024 Name: Tropical Low Identifier: 08U Data At: 0000 UTC Latitude: 17.3S Longitude: 113.7E Location Accuracy: within 35nm (65 km) Movement Towards: west northwest (298 deg) Speed of Movement: 2 knots (4 km/h) Maximum 10-Minute Wind: 25 knots (45 km/h) Maximum 3-Second Wind Gust: 45 knots (85 km/h) Central Pressure: 1000 hPa Radius of 34-knot winds NE quadrant: Radius of 34-knot winds SE quadrant: Radius of 34-knot winds SW quadrant: Radius of 34-knot winds NW quadrant: Radius of 48-knot winds NE quadrant: Radius of 48-knot winds SE quadrant: Radius of 48-knot winds SW quadrant: Radius of 48-knot winds NW quadrant: Radius of 64-knot winds: nm ( km) Radius of Maximum Winds: nm ( km) Dvorak Intensity Code: T1.5/2.0/D0.5/24HRS STT:S0.0/06HRS Pressure of outermost isobar: 1003 hPa Radius of outermost closed isobar: 160 nm (295 km) FORECAST DATA Date/Time : Location : Loc. Accuracy: Max Wind : Central Pressure (UTC) : degrees : nm (km): knots(km/h): hPa +06: 17/0600: 17.2S 113.5E: 050 (090): 025 (045): 997 +12: 17/1200: 17.2S 113.3E: 055 (105): 030 (055): 996 +18: 17/1800: 17.3S 113.1E: 060 (115): 030 (055): 996 +24: 18/0000: 17.4S 112.9E: 070 (130): 030 (055): 996 +36: 18/1200: 17.5S 112.7E: 080 (145): 030 (055): 995 +48: 19/0000: 17.4S 112.5E: 090 (160): 030 (055): 995 +60: 19/1200: 17.2S 112.1E: 100 (190): 030 (055): 996 +72: 20/0000: 16.9S 111.1E: 110 (205): 030 (055): 997 +96: 21/0000: 16.5S 108.3E: 135 (250): 040 (075): 992 +120: 22/0000: 16.5S 104.4E: 190 (350): 045 (085): 990 REMARKS: Tropical Low 08U unlikely to develop significantly in the next few days. Intensity is 25 kn based on earlier (1300 UTC) scatterometry and Dvorak. Dvorak analysis: DT is unclear. A D- trend gives MET 1.5, PAT 1.5, FT of 1.5 and CI 2.0. Recent objective guidance: ADT 51kn, AiDT 42kn, DPRINT 33kn (all 1-min average) (SATCON N/A). ADT remains higher than what earlier scatterometry indicated. Convection continues to fluctuate, and the recent isolated spots of deep convection north and south of centre, both with frequent lightning. However, significantly more deep convection is required to moisten the circulation to enable sustained deep convection about the centre and development. While it is possible the environment improves on Sunday and Monday with lower shear, the most recent NWP indicates a general delay for development until Wednesday. Somewhat surprisingly NWP suggests further intensification despite what appears to be a dry environment and only upper level outflow to the south. The official intensity forecast remains below most model guidance as a result. 08U has been moving slowly to the west as the ridge to the south is dominating the steering influences of the westerly flow to the north. The ridge is weakening so slow and erratic motion will occur until during Tuesday. The ridge should once again build from Tuesday ensuring a westerly track is maintained in the following days. Copyright Commonwealth of Australia == The next bulletin for this system will be issued by: 17/0730 UTC.
Time (AWST) Intensity Category Latitude
(decimal deg.)Longitude
(decimal deg.)Estimated Position
Accuracy (km)0hr 8 am March 17 tropical low 17.3S 113.7E 65 +6hr 2 pm March 17 tropical low 17.2S 113.5E 90 +12hr 8 pm March 17 tropical low 17.2S 113.3E 105 +18hr 2 am March 18 tropical low 17.3S 113.1E 115 +24hr 8 am March 18 tropical low 17.4S 112.9E 130 +36hr 8 pm March 18 tropical low 17.5S 112.7E 145 +48hr 8 am March 19 tropical low 17.4S 112.5E 160 +60hr 8 pm March 19 tropical low 17.2S 112.1E 190 +72hr 8 am March 20 tropical low 16.9S 111.1E 205 -
WTXS32 PGTW 170300 MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/TROPICAL CYCLONE 18S (EIGHTEEN) WARNING NR 024// RMKS/ 1. TROPICAL CYCLONE 18S (EIGHTEEN) WARNING NR 024 01 ACTIVE TROPICAL CYCLONE IN SOUTHIO MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE WIND RADII VALID OVER OPEN WATER ONLY --- WARNING POSITION: 170000Z --- NEAR 17.1S 114.2E MOVEMENT PAST SIX HOURS - 135 DEGREES AT 06 KTS POSITION ACCURATE TO WITHIN 060 NM POSITION BASED ON CENTER LOCATED BY SATELLITE PRESENT WIND DISTRIBUTION: MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT WIND RADII VALID OVER OPEN WATER ONLY REPEAT POSIT: 17.1S 114.2E --- FORECASTS: 12 HRS, VALID AT: 171200Z --- 17.2S 114.0E MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 034 KT WINDS - 000 NM NORTHEAST QUADRANT 060 NM SOUTHEAST QUADRANT 060 NM SOUTHWEST QUADRANT 000 NM NORTHWEST QUADRANT VECTOR TO 24 HR POSIT: 270 DEG/ 01 KTS --- 24 HRS, VALID AT: 180000Z --- 17.2S 113.7E MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 034 KT WINDS - 000 NM NORTHEAST QUADRANT 060 NM SOUTHEAST QUADRANT 060 NM SOUTHWEST QUADRANT 000 NM NORTHWEST QUADRANT VECTOR TO 36 HR POSIT: 290 DEG/ 02 KTS --- 36 HRS, VALID AT: 181200Z --- 17.1S 113.4E MAX SUSTAINED WINDS - 040 KT, GUSTS 050 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 034 KT WINDS - 050 NM NORTHEAST QUADRANT 070 NM SOUTHEAST QUADRANT 080 NM SOUTHWEST QUADRANT 060 NM NORTHWEST QUADRANT VECTOR TO 48 HR POSIT: 270 DEG/ 01 KTS --- EXTENDED OUTLOOK: 48 HRS, VALID AT: 190000Z --- 17.1S 113.1E MAX SUSTAINED WINDS - 040 KT, GUSTS 050 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 034 KT WINDS - 050 NM NORTHEAST QUADRANT 080 NM SOUTHEAST QUADRANT 080 NM SOUTHWEST QUADRANT 060 NM NORTHWEST QUADRANT VECTOR TO 72 HR POSIT: 275 DEG/ 03 KTS --- 72 HRS, VALID AT: 200000Z --- 17.0S 111.9E MAX SUSTAINED WINDS - 040 KT, GUSTS 050 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 034 KT WINDS - 040 NM NORTHEAST QUADRANT 080 NM SOUTHEAST QUADRANT 090 NM SOUTHWEST QUADRANT 060 NM NORTHWEST QUADRANT VECTOR TO 96 HR POSIT: 275 DEG/ 06 KTS --- LONG RANGE OUTLOOK: --- 96 HRS, VALID AT: 210000Z --- 16.7S 109.6E MAX SUSTAINED WINDS - 045 KT, GUSTS 055 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 034 KT WINDS - 060 NM NORTHEAST QUADRANT 100 NM SOUTHEAST QUADRANT 100 NM SOUTHWEST QUADRANT 070 NM NORTHWEST QUADRANT VECTOR TO 120 HR POSIT: 270 DEG/ 08 KTS --- 120 HRS, VALID AT: 220000Z --- 16.6S 106.1E MAX SUSTAINED WINDS - 045 KT, GUSTS 055 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 034 KT WINDS - 060 NM NORTHEAST QUADRANT 100 NM SOUTHEAST QUADRANT 100 NM SOUTHWEST QUADRANT 070 NM NORTHWEST QUADRANT --- REMARKS: 170300Z POSITION NEAR 17.1S 114.2E. 17MAR24. TROPICAL CYCLONE 18S (EIGHTEEN), LOCATED APPROXIMATELY 312 NM NORTH OF LEARMONTH, AUSTRALIA, HAS TRACKED SOUTHEASTWARD AT 06 KNOTS OVER THE PAST SIX HOURS. MINIMUM CENTRAL PRESSURE AT 170000Z IS 999 MB. MAXIMUM SIGNIFICANT WAVE HEIGHT AT 170000Z IS 14 FEET. NEXT WARNINGS AT 171500Z AND 180300Z. // NNNN
WDXS32 PGTW 170300 MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/PROGNOSTIC REASONING FOR TROPICAL CYCLONE 18S (EIGHTEEN) WARNING NR 024// RMKS/ 1. FOR METEOROLOGISTS. 2. 6 HOUR SUMMARY AND ANALYSIS. SUMMARY: INITIAL POSITION: 17.1S 114.2E INITIAL INTENSITY: 35 KTS GEOGRAPHIC REFERENCE: 312 NM NORTH OF LEARMONTH, AUSTRALIA MOVEMENT PAST 6 HOURS: SOUTHEASTWARD AT 06 KTS SIGNIFICANT WAVE HEIGHT: 14 FEET SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION: ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) DEPICTS LOW-LEVEL CLOUD BANDS WRAPPING INTO TROPICAL CYCLONE 18S, THOUGH THE LOW LEVEL CIRCULATION CENTER (LLCC) REMAINS OBSCURED BY PLUMES OF FLARING CONVECTION. AS EASTERLY VERTICAL WIND SHEAR (VWS) HAS DECREASED OVER THE LAST SIX HOURS TO 15-20KTS, THE VERTICAL STRUCTURE OF THE SYSTEM HAS IMPROVED SLIGHTLY. THE SYSTEM REMAINS QUASI-STATIONARY (QS) IN THE REGION, CONTINUING OCEANIC UPWELLING AND DRAINING THE OCEAN HEAT CONTENT. THE SYSTEM HAS DRIFTED TO THE SOUTHEAST WHILE REMAINING IN A COMPETING STEERING ENVIRONMENT ON THE SOUTHERN PERIPHERY OF A NEAR EQUATORIAL RIDGE (NER) TO THE NORTH AND A SUBTROPICAL RIDGE (STR) TO THE SOUTHEAST. OUTFLOW WAFTS WEAKLY POLEWARD AS WINDS ARE NOT VERY DIVERGENT ALOFT. THE INITIAL POSITION WAS ASSESSED WITH LOW CONFIDENCE BASED ON ANIMATED MSI DEPICTING WELL-DEFINED CLOUD BANDS WRAPPING FROM THE NORTHWEST INTO A CENTER BENEATH THE CONVECTION. THE INTENSITY WAS ASSESSED WITH LOW CONFIDENCE BASED ON AGENCY AND OBJECTIVE FIXES LISTED BELOW. INITIAL WIND RADII BASIS: PERSISTENCE CURRENT STEERING MECHANISM: COMPETING STEERING PATTERN. AGENCY DVORAK AND AUTOMATED FIXES: PGTW: T2.0 - 30 KTS KNES: T2.0 - 30 KTS APRF: T1.5 - 25 KTS CIMSS ADT: 51 KTS AT 170000Z FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: MARGINAL VWS: 15-20 KTS SST: 29-30 CELSIUS OUTFLOW: WEAK POLEWARD ANALYSIS CONFIDENCE: INITIAL POSITION: LOW INITIAL INTENSITY: LOW INITIAL WIND RADII: LOW 3. FORECAST REASONING. SIGNIFICANT FORECAST CHANGES: THERE ARE NO SIGNIFICANT CHANGES TO THE FORECAST FROM THE PREVIOUS WARNING. FORECAST DISCUSSION: TC 18S IS FORECAST TO REMAIN IN A QS STATE FOR THE NEXT 48 HOURS BEFORE BEING DRIVEN WESTWARD BY A BUILDING NER TO THE SOUTHEAST OVER CONTINENTIAL AUSTRALIA. AS THE SYSTEM PICKS UP TRACK SPEED BY TAU 72, THE SYSTEM IS EXPECTED TO REACH 8KTS BY THE END OF THE FORECAST PERIOD. TC 18S IS FORECAST TO STRUGGLE TO INTENSIFY IN THE NEAR-TERM AND REMAIN ALMOST STAGNANT FOR THE FIRST 24 HOURS. AS THE SYSTEM MOVES AWAY FROM THE REGION BETWEEN TAU 48-72, VWS SHOULD REMAIN FAVORABLE ALLOWING FOR SLOW INTENSIFICATION DESPITE CONTINUING INTO A REGION OF RELATIVELY COOLER WATERS AND LOWER OCEAN HEAT CONTENT. BY THE END OF THE FORECAST PERIOD, THE SYSTEM IS EXPECTED TO INCREASE TO A PEAK OF 45KTS AS THE ENVIRONMENT IMPROVES. MODEL DISCUSSION: DETERMINISTIC MODEL GUIDANCE IS IN GENERALLY GOOD AGREEMENT THAT THE SYSTEM WILL REMAIN QUASI-STATIONARY BEFORE TRACKING TO THE WEST BETWEEN THE 48-72 HOUR POINT. THE MAXIMUM CROSS TRACK SPREAD BY THE END OF THE FORECAST OPENS TO 400NM BY THE END OF THE FORECAST PERIOD, WITH ECM2 TO THE NORTH AND NAVGEM TO THE SOUTH. THE INTENSITY GUIDANCE HAS CHANGED DRASTICALLY OVER THE LAST SIX HOURS, WITH HAFS-A DROPPING FROM A PEAK OF 150KTS ON THE 161200Z RUN TO A PEAK OF 40KTS IN THE CURRENT RUN. JTWC SHIPS GUIDANCE AND HWRF BOTH REMAIN HIGH, PEAKING AT 85KTS BY TAU 120. THE SIGNIFICANT DEVIATION BETWEEN MODEL RUNS HAS CAUSED GREAT UNCERTAINTY AND LOW CONFIDENCE IN THE INTENSITY FORECAST. FORECAST CONFIDENCE: TRACK 0 - 72 HR: LOW TRACK 72-120 HR: LOW INTENSITY 0 - 72 HR: LOW INTENSITY 72-120 HR: LOW// NNNN
最后于 2024-03-17 15:35:00 被ygsj24编辑 ，原因： -
AXAU01 APRF 170648 IDW27600 TROPICAL CYCLONE TECHNICAL BULLETIN: AUSTRALIA - WESTERN REGION Issued by AUSTRALIAN BUREAU OF METEOROLOGY TROPICAL CYCLONE WARNING CENTRE at: 0648 UTC 17/03/2024 Name: Tropical Low Identifier: 08U Data At: 0600 UTC Latitude: 17.3S Longitude: 112.9E Location Accuracy: within 30nm (55 km) Movement Towards: west (270 deg) Speed of Movement: 8 knots (14 km/h) Maximum 10-Minute Wind: 25 knots (45 km/h) Maximum 3-Second Wind Gust: 45 knots (85 km/h) Central Pressure: 999 hPa Radius of 34-knot winds NE quadrant: Radius of 34-knot winds SE quadrant: Radius of 34-knot winds SW quadrant: Radius of 34-knot winds NW quadrant: Radius of 48-knot winds NE quadrant: Radius of 48-knot winds SE quadrant: Radius of 48-knot winds SW quadrant: Radius of 48-knot winds NW quadrant: Radius of 64-knot winds: nm ( km) Radius of Maximum Winds: nm ( km) Dvorak Intensity Code: T2.0/2.0/D1.0/24HRS STT:D0.5/06HRS Pressure of outermost isobar: 1002 hPa Radius of outermost closed isobar: 140 nm (260 km) FORECAST DATA Date/Time : Location : Loc. Accuracy: Max Wind : Central Pressure (UTC) : degrees : nm (km): knots(km/h): hPa +06: 17/1200: 17.3S 112.8E: 045 (080): 030 (055): 999 +12: 17/1800: 17.3S 112.7E: 055 (100): 030 (055): 998 +18: 18/0000: 17.4S 112.6E: 060 (110): 030 (055): 997 +24: 18/0600: 17.4S 112.5E: 070 (125): 030 (055): 997 +36: 18/1800: 17.5S 112.4E: 075 (135): 030 (055): 997 +48: 19/0600: 17.5S 112.1E: 090 (165): 030 (055): 998 +60: 19/1800: 17.3S 111.4E: 100 (180): 030 (055): 997 +72: 20/0600: 16.9S 110.2E: 110 (210): 035 (065): 996 +96: 21/0600: 16.7S 107.2E: 140 (260): 040 (075): 992 +120: 22/0600: 16.7S 103.2E: 175 (320): 045 (085): 992 REMARKS: Tropical Low 08U unlikely to develop significantly in the next few days. Intensity is 25 kn based on earlier scatterometry (HSCAT 2253 UTC) and Dvorak. Dvorak analysis: DT is unclear. A D trend gives MET 2.0, PAT 2.0, FT of 2.0 and CI 2.0. Recent objective guidance: ADT 47kn, AiDT 39kn, DPRINT 31kn DMINT 31kn (all 1-min average) (SATCON N/A). While ADT is becoming more consistent with scatterometry it remains higher than what this indicates. Convection continues to fluctuate, recently there has been some improved deep convection to the northwest of the centre and isolated spots to the south. However, significantly more deep convection is still required to moisten the circulation to enable sustained deep convection about the centre and development. While it is possible the environment improves on Monday with lower shear, the most recent NWP continues to delay development until Wednesday. Somewhat surprisingly, NWP suggests further intensification despite what appears to be a dry environment and only upper level outflow to the south. The official intensity forecast remains below most model guidance as a result. 08U has been moving to the west under the influence of a weak steering ridge to the south. There is some westerly flow to the north slowing the motion of 08U, however this influence is easing and hence westerly motion is increasing, though it is still not particularly fast. From Tuesday the ridge will once again build maintaining a westerly track and increasing the speed. Copyright Commonwealth of Australia == The next bulletin for this system will be issued by: 17/1330 UTC.
Time (AWST) Intensity Category Latitude
(decimal deg.)Longitude
(decimal deg.)Estimated Position
Accuracy (km)0hr 2 pm March 17 tropical low 17.3S 112.9E 55 +6hr 8 pm March 17 tropical low 17.3S 112.8E 80 +12hr 2 am March 18 tropical low 17.3S 112.7E 100 +18hr 8 am March 18 tropical low 17.4S 112.6E 110 +24hr 2 pm March 18 tropical low 17.4S 112.5E 125 +36hr 2 am March 19 tropical low 17.5S 112.4E 135 +48hr 2 pm March 19 tropical low 17.5S 112.1E 165 +60hr 2 am March 20 tropical low 17.3S 111.4E 180 +72hr 2 pm March 20 tropical low 16.9S 110.2E 210 -
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WTXS32 PGTW 170900 MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/TROPICAL CYCLONE 18S (EIGHTEEN) WARNING NR 025// RMKS/ 1. TROPICAL CYCLONE 18S (EIGHTEEN) WARNING NR 025 01 ACTIVE TROPICAL CYCLONE IN SOUTHIO MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE WIND RADII VALID OVER OPEN WATER ONLY --- WARNING POSITION: 170600Z --- NEAR 17.1S 113.0E MOVEMENT PAST SIX HOURS - 280 DEGREES AT 07 KTS POSITION ACCURATE TO WITHIN 050 NM POSITION BASED ON CENTER LOCATED BY SATELLITE PRESENT WIND DISTRIBUTION: MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 034 KT WINDS - 055 NM NORTHEAST QUADRANT 055 NM SOUTHEAST QUADRANT 070 NM SOUTHWEST QUADRANT 080 NM NORTHWEST QUADRANT REPEAT POSIT: 17.1S 113.0E --- FORECASTS: 12 HRS, VALID AT: 171800Z --- 17.1S 112.7E MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 034 KT WINDS - 060 NM NORTHEAST QUADRANT 050 NM SOUTHEAST QUADRANT 050 NM SOUTHWEST QUADRANT 070 NM NORTHWEST QUADRANT VECTOR TO 24 HR POSIT: 200 DEG/ 02 KTS --- 24 HRS, VALID AT: 180600Z --- 17.4S 112.6E MAX SUSTAINED WINDS - 040 KT, GUSTS 050 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 034 KT WINDS - 060 NM NORTHEAST QUADRANT 070 NM SOUTHEAST QUADRANT 080 NM SOUTHWEST QUADRANT 060 NM NORTHWEST QUADRANT VECTOR TO 36 HR POSIT: 225 DEG/ 01 KTS --- 36 HRS, VALID AT: 181800Z --- 17.5S 112.5E MAX SUSTAINED WINDS - 040 KT, GUSTS 050 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 034 KT WINDS - 030 NM NORTHEAST QUADRANT 060 NM SOUTHEAST QUADRANT 070 NM SOUTHWEST QUADRANT 050 NM NORTHWEST QUADRANT VECTOR TO 48 HR POSIT: 285 DEG/ 02 KTS --- EXTENDED OUTLOOK: 48 HRS, VALID AT: 190600Z --- 17.4S 112.1E MAX SUSTAINED WINDS - 040 KT, GUSTS 050 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 034 KT WINDS - 030 NM NORTHEAST QUADRANT 050 NM SOUTHEAST QUADRANT 070 NM SOUTHWEST QUADRANT 050 NM NORTHWEST QUADRANT VECTOR TO 72 HR POSIT: 280 DEG/ 05 KTS --- 72 HRS, VALID AT: 200600Z --- 17.0S 110.2E MAX SUSTAINED WINDS - 040 KT, GUSTS 050 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 034 KT WINDS - 060 NM NORTHEAST QUADRANT 050 NM SOUTHEAST QUADRANT 070 NM SOUTHWEST QUADRANT 070 NM NORTHWEST QUADRANT VECTOR TO 96 HR POSIT: 275 DEG/ 08 KTS --- LONG RANGE OUTLOOK: --- 96 HRS, VALID AT: 210600Z --- 16.7S 106.8E MAX SUSTAINED WINDS - 045 KT, GUSTS 055 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 034 KT WINDS - 070 NM NORTHEAST QUADRANT 070 NM SOUTHEAST QUADRANT 090 NM SOUTHWEST QUADRANT 080 NM NORTHWEST QUADRANT VECTOR TO 120 HR POSIT: 265 DEG/ 10 KTS --- 120 HRS, VALID AT: 220600Z --- 17.0S 102.6E MAX SUSTAINED WINDS - 045 KT, GUSTS 055 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 034 KT WINDS - 060 NM NORTHEAST QUADRANT 080 NM SOUTHEAST QUADRANT 090 NM SOUTHWEST QUADRANT 060 NM NORTHWEST QUADRANT --- REMARKS: 170900Z POSITION NEAR 17.1S 112.9E. 17MAR24. TROPICAL CYCLONE 18S (EIGHTEEN), LOCATED APPROXIMATELY 318 NM NORTH OF LEARMONTH, AUSTRALIA, HAS TRACKED WESTWARD AT 07 KNOTS OVER THE PAST SIX HOURS. MINIMUM CENTRAL PRESSURE AT 170600Z IS 997 MB. MAXIMUM SIGNIFICANT WAVE HEIGHT AT 170600Z IS 15 FEET. NEXT WARNINGS AT 171500Z, 172100Z, 180300Z AND 180900Z.// NNNN
WDXS32 PGTW 170900 MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/PROGNOSTIC REASONING FOR TROPICAL CYCLONE 18S (EIGHTEEN) WARNING NR 025// RMKS/ 1. FOR METEOROLOGISTS. 2. 6 HOUR SUMMARY AND ANALYSIS. SUMMARY: INITIAL POSITION: 17.1S 113.0E INITIAL INTENSITY: 35 KTS GEOGRAPHIC REFERENCE: 318 NM NORTH OF LEARMONTH, AUSTRALIA MOVEMENT PAST 6 HOURS: WESTWARD AT 07 KTS SIGNIFICANT WAVE HEIGHT: 15 FEET SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION: ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) DEPICTS TROPICAL CYCLONE (TC) 18S (EIGHTEEN) WITH DISORGANIZED FLARING CONVECTION IN THE WESTERN PERIPHERY OF A PARTIALLY EXPOSED AND BROAD LOW-LEVEL CIRCULATION CENTER (LLCC). THE CURRENT ENVIRONMENT IS ASSESSED AS MARGINAL BASED ON THE WEAK OUTFLOW ALOFT AND DRY AIR BEING ENTRAINED INTO THE SYSTEM FROM THE NORTH, WHICH IS OFFSET BY WARM (29-30C) SEA SURFACE TEMPERATURES AND LOW (10-15 KTS) VERTICAL WIND SHEAR. A 170518Z GMI 37 GHZ SATELLITE MICROWAVE IMAGE, ALONG WITH ANIMATED MSI, HELPED PLACE THE INITIAL POSITION WITH HIGH CONFIDENCE. THE INITIAL INTENSITY OF 35 KTS IS ASSESSED WITH LOW CONFIDENCE BASED ON OBJECTIVE AND SUBJECTIVE DVORAK ESTIMATES LISTED BELOW. INITIAL WIND RADII BASIS: PERSISTENCE CURRENT STEERING MECHANISM: COMPETING STEERING PATTERN. AGENCY DVORAK AND AUTOMATED FIXES: PGTW: T2.0 - 30 KTS KNES: T2.0 - 30 KTS DEMS: T2.0 - 30 KTS APRF: T2.0 - 30 KTS CIMSS AIDT: 39 KTS AT 170600Z CIMSS DMINT: 32 KTS AT 170557Z CIMSS MW SOUNDERS: 38KTS AT 170626Z FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: MARGINAL VWS: 10-15 KTS SST: 29-30 CELSIUS OUTFLOW: WEAK WESTWARD ANALYSIS CONFIDENCE: INITIAL POSITION: HIGH INITIAL INTENSITY: LOW INITIAL WIND RADII: LOW 3. FORECAST REASONING. SIGNIFICANT FORECAST CHANGES: THERE ARE NO SIGNIFICANT CHANGES TO THE FORECAST FROM THE PREVIOUS WARNING. FORECAST DISCUSSION: TC 18S IS CURRENTLY TRACKING WESTWARD WHILE LOCATED IN A WEAK STEERING ENVIRONMENT. TC 18S IS FORECAST TO TRACK SLOWLY WESTWARD UNTIL TAU 12. AFTER TAU 12, THE SYSTEM IS FORECAST TO TURN SOUTHWESTWARD AND CONTINUE ON A VERY SLOW SOUTHWESTWARD TRACK UNTIL TAU 36. AFTER TAU 36, THE STEERING ENVIRONMENT BECOMES MORE DEFINED WITH A SUBTROPICAL RIDGE (STR) POSITIONED SOUTH OF THE SYSTEM, CAUSING TRACK SPEEDS TO INCREASE. AS A RESULT, THE JTWC FORECAST TRACKS TC 18S WESTWARD, ALONG THE NORTHERN PERIPHERY OF THE STR THROUGHOUT THE REMAINDER OF THE FORECAST PERIOD. INTENSITY IS FORECAST TO VERY GRADUALLY RISE OVER THE FORECAST INTERVAL GIVEN A MARGINAL TO MARGINALLY FAVORABLE ENVIRONMENT ALONG TRACK AND REACH 45 KTS BY TAU 96, SUSTAINING THROUGH TAU 120. MODEL DISCUSSION: NUMERICAL MODEL GUIDANCE IS IN BETTER AGREEMENT CONCERNING TRACK GUIDANCE. WITH THE EXCEPTION OF NAVGEM, WHICH TRACKS THE SYSTEM SOUTHWESTWARD AFTER TAU 72 VICE WESTWARD, THERE IS A 120 NM CROSS-TRACK SPREAD AT TAU 72 AND A 225 NM CROSS-TRACK SPREAD AT TAU 120. EVEN WITH THE JTWC CONSENSUS MEMBERS BECOMING MORE ALIGNED, THE JTWC TRACK FORECAST IS PLACED WITH OVERALL LOW CONFIDENCE PRIMARILY DUE TO THE WEAK STEERING ENVIRONMENT THAT THE SYSTEM IS LOCATED IN. THE JTWC INTENSITY FORECAST IS ASSESSED WITH OVERALL LOW CONFIDENCE AS WELL. THIS IS MAINLY DUE TO GFS HAVING THE SYSTEM ATTAIN AROUND 65 KTS AT TAU 96, WHILE COAMPS-TC, HAFS-A, AND HWRF ALL KEEP THE SYSTEM AROUND 35-45 KTS THROUGHOUT THE FORECAST PERIOD. FORECAST CONFIDENCE: TRACK 0 - 72 HR: LOW TRACK 72-120 HR: LOW INTENSITY 0 - 72 HR: LOW INTENSITY 72-120 HR: LOW// NNNN
最后于 2024-03-17 18:00:00 被ygsj24编辑 ，原因： -
Time (AWST) Intensity Category Latitude
(decimal deg.)Longitude
(decimal deg.)Estimated Position
Accuracy (km)0hr 8 pm March 17 tropical low 17.2S 112.4E 55 +6hr 2 am March 18 tropical low 17.2S 112.6E 80 +12hr 8 am March 18 tropical low 17.3S 112.5E 100 +18hr 2 pm March 18 tropical low 17.6S 112.5E 120 +24hr 8 pm March 18 tropical low 17.8S 112.4E 130 +36hr 8 am March 19 tropical low 17.6S 112.1E 145 +48hr 8 pm March 19 tropical low 17.3S 111.7E 165 +60hr 8 am March 20 tropical low 17.1S 110.7E 170 +72hr 8 pm March 20 tropical low 17.1S 109.5E 200 -
WTXS32 PGTW 171500 MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/TROPICAL CYCLONE 18S (EIGHTEEN) WARNING NR 026// RMKS/ 1. TROPICAL CYCLONE 18S (EIGHTEEN) WARNING NR 026 01 ACTIVE TROPICAL CYCLONE IN SOUTHIO MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE WIND RADII VALID OVER OPEN WATER ONLY --- WARNING POSITION: 171200Z --- NEAR 17.1S 112.8E MOVEMENT PAST SIX HOURS - 270 DEGREES AT 02 KTS POSITION ACCURATE TO WITHIN 060 NM POSITION BASED ON CENTER LOCATED BY SATELLITE PRESENT WIND DISTRIBUTION: MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 034 KT WINDS - 055 NM NORTHEAST QUADRANT 055 NM SOUTHEAST QUADRANT 070 NM SOUTHWEST QUADRANT 080 NM NORTHWEST QUADRANT REPEAT POSIT: 17.1S 112.8E --- FORECASTS: 12 HRS, VALID AT: 180000Z --- 17.3S 112.6E MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 034 KT WINDS - 050 NM NORTHEAST QUADRANT 070 NM SOUTHEAST QUADRANT 070 NM SOUTHWEST QUADRANT 050 NM NORTHWEST QUADRANT VECTOR TO 24 HR POSIT: 210 DEG/ 02 KTS --- 24 HRS, VALID AT: 181200Z --- 17.6S 112.4E MAX SUSTAINED WINDS - 040 KT, GUSTS 050 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 034 KT WINDS - 030 NM NORTHEAST QUADRANT 050 NM SOUTHEAST QUADRANT 080 NM SOUTHWEST QUADRANT 050 NM NORTHWEST QUADRANT VECTOR TO 36 HR POSIT: 290 DEG/ 02 KTS --- 36 HRS, VALID AT: 190000Z --- 17.5S 112.1E MAX SUSTAINED WINDS - 040 KT, GUSTS 050 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 034 KT WINDS - 030 NM NORTHEAST QUADRANT 060 NM SOUTHEAST QUADRANT 090 NM SOUTHWEST QUADRANT 060 NM NORTHWEST QUADRANT VECTOR TO 48 HR POSIT: 300 DEG/ 03 KTS --- EXTENDED OUTLOOK: 48 HRS, VALID AT: 191200Z --- 17.2S 111.6E MAX SUSTAINED WINDS - 045 KT, GUSTS 055 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 034 KT WINDS - 040 NM NORTHEAST QUADRANT 060 NM SOUTHEAST QUADRANT 090 NM SOUTHWEST QUADRANT 060 NM NORTHWEST QUADRANT VECTOR TO 72 HR POSIT: 280 DEG/ 05 KTS --- 72 HRS, VALID AT: 201200Z --- 16.8S 109.4E MAX SUSTAINED WINDS - 050 KT, GUSTS 065 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 050 KT WINDS - 010 NM NORTHEAST QUADRANT 010 NM SOUTHEAST QUADRANT 020 NM SOUTHWEST QUADRANT 020 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 050 NM NORTHEAST QUADRANT 060 NM SOUTHEAST QUADRANT 090 NM SOUTHWEST QUADRANT 090 NM NORTHWEST QUADRANT VECTOR TO 96 HR POSIT: 275 DEG/ 08 KTS --- LONG RANGE OUTLOOK: --- 96 HRS, VALID AT: 211200Z --- 16.6S 106.1E MAX SUSTAINED WINDS - 055 KT, GUSTS 070 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 050 KT WINDS - 030 NM NORTHEAST QUADRANT 030 NM SOUTHEAST QUADRANT 030 NM SOUTHWEST QUADRANT 040 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 060 NM NORTHEAST QUADRANT 060 NM SOUTHEAST QUADRANT 080 NM SOUTHWEST QUADRANT 090 NM NORTHWEST QUADRANT VECTOR TO 120 HR POSIT: 265 DEG/ 11 KTS --- 120 HRS, VALID AT: 221200Z --- 17.0S 101.6E MAX SUSTAINED WINDS - 060 KT, GUSTS 075 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 050 KT WINDS - 030 NM NORTHEAST QUADRANT 040 NM SOUTHEAST QUADRANT 040 NM SOUTHWEST QUADRANT 040 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 060 NM NORTHEAST QUADRANT 100 NM SOUTHEAST QUADRANT 090 NM SOUTHWEST QUADRANT 080 NM NORTHWEST QUADRANT --- REMARKS: 171500Z POSITION NEAR 17.1S 112.7E. 17MAR24. TROPICAL CYCLONE 18S (EIGHTEEN), LOCATED APPROXIMATELY 321 NM NORTH-NORTHWEST OF LEARMONTH, AUSTRALIA, HAS TRACKED WESTWARD AT 02 KNOTS OVER THE PAST SIX HOURS. MINIMUM CENTRAL PRESSURE AT 171200Z IS 997 MB. MAXIMUM SIGNIFICANT WAVE HEIGHT AT 171200Z IS 15 FEET. NEXT WARNINGS AT 172100Z, 180300Z, 180900Z AND 181500Z.// NNNN
WDXS32 PGTW 171500 MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/PROGNOSTIC REASONING FOR TROPICAL CYCLONE 18S (EIGHTEEN) WARNING NR 026// RMKS/ 1. FOR METEOROLOGISTS. 2. 6 HOUR SUMMARY AND ANALYSIS. SUMMARY: INITIAL POSITION: 17.1S 112.8E INITIAL INTENSITY: 35 KTS GEOGRAPHIC REFERENCE: 321 NM NORTH-NORTHWEST OF LEARMONTH, AUSTRALIA MOVEMENT PAST 6 HOURS: WESTWARD AT 02 KTS SIGNIFICANT WAVE HEIGHT: 15 FEET SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION: ANIMATED ENHANCED INFRARED (EIR) SATELLITE IMAGERY DEPICTS TROPICAL CYCLONE (TC) 18S (EIGHTEEN) WITH A SLIGHTLY IMPROVED CONVECTIVE STRUCTURE OVER THE PAST 6 HOURS. THOUGH FLARING DEEP CONVECTIVE BURSTS HAVE BECOME MORE PERSISTENT, THE OVERALL STRUCTURE OF THE SYSTEM REMAINS RATHER DISORGANIZED. A 171015Z SSMIS 91 GHZ SATELLITE MICROWAVE IMAGE REVEALS DEEP CONVECTION IN THE EASTERN PERIPHERY OF THE LOW-LEVEL CIRCULATION CENTER (LLCC) AND CONVECTIVE BANDING WRAPPING INTO THE SYSTEM IN THE SOUTHERN SEMICIRCLE. THE CURRENT ENVIRONMENT IS ASSESSED AS MARGINAL BASED ON THE WEAK POLEWARD OUTFLOW ALOFT AND DRY AIR ENTRAINING INTO THE SYSTEM, WHICH IS OFFSET BY LOW (10-15 KTS) VERTICAL WIND SHEAR AND WARM (29-30 C) SEA SURFACE TEMPERATURES. THE INITIAL POSITION IS PLACED WITH LOW CONFIDENCE BASED ON THE AFOREMENTIONED SSMIS MICROWAVE IMAGE AND ANIMATED EIR. THE INITIAL INTENSITY OF 35 KTS IS ASSESSED WITH LOW CONFIDENCE BASED ON OBJECTIVE AND SUBJECTIVE INTENSITY ESTIMATES LISTED BELOW. INITIAL WIND RADII BASIS: PERSISTENCE CURRENT STEERING MECHANISM: COMPETING STEERING ENVIRONMENT AGENCY DVORAK AND AUTOMATED FIXES: PGTW: T2.5 - 35 KTS KNES: T2.0 - 30 KTS CIMSS SATCON: 37 KTS AT 170900Z CIMSS AIDT: 37 KTS AT 171200Z FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: MARGINAL VWS: 10-15 KTS SST: 29-30 CELSIUS OUTFLOW: WEAK POLEWARD ANALYSIS CONFIDENCE: INITIAL POSITION: LOW INITIAL INTENSITY: LOW INITIAL WIND RADII: LOW 3. FORECAST REASONING. SIGNIFICANT FORECAST CHANGES: THERE ARE NO SIGNIFICANT CHANGES TO THE FORECAST FROM THE PREVIOUS WARNING. FORECAST DISCUSSION: TC 18S IS FORECAST TO BEGIN TRACKING SLOWLY SOUTHWESTWARD OVER THE NEXT 24 HOURS. AFTER TAU 24, TC 18S IS FORECAST TO TRACK SLOWLY NORTHWESTWARD THROUGH TAU 48 AS THE SYSTEM BEGINS TO FEEL THE STEERING EFFECTS OF THE SUBTROPICAL RIDGE (STR) THAT PROPOGATES FROM THE WEST. AS THE STR BUILDS TO THE SOUTH, THE STEERING MECHANISM IS EXPECTED TO BECOME MUCH MORE DEFINED AND THE TRACK SPEED IS ANTICIPATED TO INCREASE AS THE SYSTEM TRACKS WESTWARD ALONG THE NORTHERN PERIPHERY OF THE STR THROUGH THE REMAINDER OF THE FORECAST PERIOD. TC 18S IS FORECAST TO MAINTAIN ITS INTENSITY OF 35 KTS UNTIL TAU 12 AND INCREASE TO 45 KTS AROUND TAU 48 DUE TO A DECREASE IN VERTICAL WIND SHEAR. AFTER TAU 48, TC 18S IS FORECAST TO BEGIN A GRADUAL INTENSIFICATION PHASE THROUGHOUT THE REMAINDER OF THE FORECAST PERIOD IN RESPONSE TO LOW VERTICAL WIND SHEAR AND THE VORTEX MOISTENING. MODEL DISCUSSION: NUMERICAL MODEL GUIDANCE IS IN FAIR AGREEMENT REGARDING THE TRACK FORECAST. WITH THE EXCEPTION OF NAVGEM, WHICH TRACKS THE SYSTEM SOUTHWESTWARD VICE WESTWARD, THERE IS A 110 NM SPREAD AT TAU 72 AND A 160 NM CROSS-TRACK SPREAD AT TAU 120. THE REST OF JTWC CONSENSUS MEMBERS FOLLOW A SIMILAR TRACK AS DESCRIBED IN THE FORECAST DISCUSSION. THERE IS POOR AGREEMENT CONCERNING INTENSITY GUIDANCE FOR TC 18S. HAFS-A AND HWRF BOTH SHOW THE SYSTEM QUICKLY INTENSIFYING AFTER TAU 48 AND REACHING OVER 90 KTS BY TAU 96. CONVERSELY, COAMPS-TC CONTINUES TO KEEP TC 18S AROUND 30-45 KTS THROUGHOUT THE FORECAST INTERVAL. AS SUCH, THE JTWC INTENSITY FORECAST IS ASSESSED WITH OVERALL LOW CONFIDENCE. FORECAST CONFIDENCE: TRACK 0 - 72 HR: MEDIUM TRACK 72-120 HR: MEDIUM INTENSITY 0 - 72 HR: LOW INTENSITY 72-120 HR: LOW// NNNN
最后于 2024-03-18 06:00:00 被ygsj24编辑 ，原因：
